The nickname "Free State" was created by Hamilton Owens, editor of the Baltimore Sun. In 1923, Georgia Congressman William D. Upshaw, a firm supporter of Prohibition, denounced Maryland as a traitor to the Union for refusing to pass a State enforcement act. Mr. Owens thereupon wrote a mock-serious editorial entitled "The Maryland Free State," arguing that Maryland should secede from the Union rather than prohibit the sale of liquor.

Now, I'm wondering if the other nickname is related to other illicit substances.